Couch-roll.



F. H. Home am.y c. TH'0MAs,-JR.

coucH ROLL. APPLICATION FILED AUG.23, l9l5.

Patented May 29, 1917.

Suva/$051.

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. UNITED sTATfsrATENT OFFICE...`

FRANK'H. Honneur AND coMAnonEo.- THOMAS, JR., or GREEN-BAY, WISCONSIN.

TofaZZ whom 'it may concern: f Be it known that we, FRANK H. I-IoBnRG and CoMADoRE C. THOMAS, Jr., citizens of the United States, residing at Green Bay, county of Brown, and State of Wisconsin, haveinvented new and useful Improvements in Couch-Rolls,1of which the following is a'specification.. Y Our 'invention relates to .improvements in couch rolls. i

The ordinary suction couch roll comprises a hollow cylinder covered Vwith fine wire, felt or equivalent foraminous material through which water may be drawn by suction, air and water being continuously withdrawn from the interior of the cylinder yby a suitable pump. In these structures the outer cylinder covering or jacket performs no function except to Support the pulp carrying belt `or apron and :allow the passage of water through it. But we have discovered that muchbetter results can-be obtained by employing an elastic covering of absorbent material Jwhich will be compressed by the pressure of the ulp carrying belt orapron and will quic y expand and` resume its original form when such pressure is relieved in a manner to maintain contact with the belt or apron in the angle between the belt or apron and the cylinder, where the apron leaves the cylinder tangentially. We have discovered that by using such a covering, the expansion Yof thematerial will create suction suicient to absorb considerable quantities of water fromv cylinder. Also that the presence of the rela-A tively large quantity of water absorbed by such a jacket tends to exclude airy and therefore increases the eii'ective vacuum within the cylinder, it being well known that the air has heretofore entered the cylinder on the side where the apron is out of contact therewith much morefreely than on the side which is covered by the apron.

We have also discovered that an elastic covering jacket of absorbent material may be employed upon a solid roller and utilized to extract water from the apron and pulp carried thereby, owing to the fact that the jacket creates its own suction to absorb water from the apron in the zone of divercocon-noni..

l Specification of Letters Patent.v

k1;"atente'd. May 29, 191.7.

Application med Augustas, 1915. iseriarNoAasai. f

gence, whereas" on the other side where the apron comes into. initial contact with the jacket, the compression of the jacket by the apron eXpels the'water. It will of course be understood that the pulp is fed to the apron along lan intermediate zone where the jacket is under full compression as exerted by the apron, the water 'previously absorbed by that portion vof the jacket having already been expelled by the apron pressure and the rexpansion of. the jacket taking placefshortly afterthe deposit of the pulp uponthe apron. To secure the desired results it-is ofcoursenecessary that a material be employed which will not mat, butwill permanently retainV its elastic and absorbent qualities. -l

The object of our invention is therefore to increase the efiiciency of suction couch rolls by providing such rolls, whether. hollowl or solid, with an elastic jacketof absorbent'material capable 'of-'permanently retaining its elastic and absorbent qualities.

In the drawings- Figure 1 is an endview, partially in transverse section, showing a lsuction couch roll embodying our invention.

Fig. 2 is a perspective View of one end` portion of a couch roll ofthe solid cylinder type embodying our invention.A

Fig. 3 is a view, showing a the jacket developed. ,v A vLike parts are identified by the same reference characters throughout the several views.

The suction couchroll illustrated in Fig. 1 embodies a central tubular shaft 1" through which the suction is applied, and a cylinder 2 i supported from the shaft by radially disposed tubular spokes 3, the periphery of the cylinder 2 being covered with a built up structure of wire and supporting members of progressively diminishing cross section, such as are shown and ldescribed in Vour former v application, led April 19, 1912, Serial No.

Vitself of continuously absorbing moisture from the pulpv apron 4, whereas the jacket 5 illustrated in Fig, 1 is a thickknitted jacket composed of thick strands 'of loosely twisted woolen yarn. We have discovered that a cated by the arrows and the pulp-delivering woven or knitted woolen jacket possesses the elastic qualities above mentioned and that it is capable of continuous expansion and contraction for an indefinite period ofv time. Also that when vexpanding in the angle where the apron leaves the cylinder tangentially, this woolen jacket will rapidly absorb water from the apron and the pulp carried thereby independently of the suce tion exerted from the interior of the cylinder Y due to the maintenance of a partial vacuum therein. The water thus absorbed by the jacket also tends to exclude air from the cylinder on that side which is not covered by the apron, although of course this exclusion will become less and less effective as the water is withdrawn into the cylinder. On the side'where the apron initially contacts with the cylinder, the compression of the jacket by the apron greatly facilitates the withdrawal of the residue of the water in the jacket,v so that by the time any given portion of the jacket reaches the point where fresh pulp is delivered upon the apron, the jacket will have been compressed and'dried to a point where it will possess substantially a maximum absorbing capacity and will therefore, as above stated, withdraw large quantities of water from the apron 4: and the pulp 6 as soon as the pressure of the apron begins to reduce.

In the construction as illustrated in Fig. 1, the moisture absorbing Zone above described and in which the jacket absorbs water by its own suction, is indicated between the points a-Z The jacket compressing Zone is indicated between the points che?, the direction in which the apron travels being indi- Gopies of this patent may be obtained for wheel being indicated at e.

v In the structure shown in Fig. 2, the cylinder 7 is a solid cylinder. The jacket 8 is similar to the jacket 5, shown in Fig. l, and

"is composed of woven or knitted material having the elastic qualities of a woolen jacket, the strands; preferably being large and coarse or loosely twisted, so as to secure the most effective moisture absorbing action. The operation of this jacket 8 is the same as above described .with reference to Fig. l, except that' the water is not expelled by'- being drawn into the interior of the cylinder and in fact is not expelled at all along that portion of the cylinder not covered by the apron, but on the contrary in the cylinder shown in Fig. 2, the water is expelled very rapidly in the Zone where the apron comes into initial contact with 'the jacket and compresses the jacket between it and the cylinder surface.

We claim- 1. A suction roll covering, consisting of a knit sleeve, said sleeve adapted to be pulled over a suction roll and cover the periphery thereof, substantially as set forth.

2.A suction roll covering, consisting of a coarsely knit woolen sleeve, said sleeve adapted to be pulled over a suction roll and cover the periphery thereof, substantially as described.

In testimony whereof we aflix our signatures in the presence of two witnesses.

FRANK I-I. HOBERG. COMADORE C. THMAS, JR. Witnesses:

WARD E. BLACK, LOUIS J. DoBnY.

five cents each, by addressing the Commissioner of Patents, Washington, D. C. v 

